Cosmetic compositions such as shaving creams, hair mousses, spray foams, foaming lotions and foaming creams are aimed to be dispensed or sprayed as foams and applied on the human skin or hair. These products are described in the present invention as "leave-on foaming cosmetic products". One common characteristic desired for these leave-on foaming cosmetic products is a foam having favorable characteristics to the consumer such as voluminous and stable foaming, with smooth and mild touch to the skin and hair.
Leave-on foaming cosmetic compositions for hair are usually referred to as "mousses", which term will be used in the present invention. Hair mousses were born in Europe in the early 1980s. Hair mousses are fundamentally an aerosol foam, however, non-aerosol foams are also known. The general appeal of hair mousses can be largely attributed to the ease of application and controlled amount of product which are possible from mousse formulations. Hair mousse compositions are generally dispensed by a compressible dispenser or a valve and applied to the user's hand or a specifically designed comb and spread through the hair. Alternatively, hair mousse compositions can be directly applied to the hair by dispensing through nozzles. Hair mousses are formulated for the purpose of styling, setting, and arranging, or for other purposes such as shampooing, conditioning, treating, dyeing, and combinations thereof.
In recent years, some consumers have expressed a desire to have "alcohol-free" hair mousse products because of concerns relating to drying of the hair, or concerns of volatile solvents being emitted to the environment. In this context, alcohol refers to volatile primary alcohols having about 1 to 6 carbons, particularly ethanol. Alcohol is used in mousses for a number of reasons. First, the presence of volatile alcohol can aid styling by decreasing drying time. However, it is assumed that this drying has raised the concerns of some consumers that alcohol is also drying hair. Second, alcohol aids foam breakage as the mousse is spread throughout the hair. It is known that foam breakage is a result of the ability of alcohol to act as a defoaming agent. Third, alcohol itself improves product preservation. Fourth, alcohol enhances the compatibility of the concentrate with the propellant, and acts as a solubility bridge between the resin and the water base. Fifth, alcohol is a good solvent for dissolving oil base ingredients such as conditioning fatty alcohols. Consequently, elimination of alcohol from the formulation may affect product performance. Thus, there is a desire to provide a foaming agent which can be used in hair mousse compositions with or without alcohol.
The species and level of preservatives are also known to affect product performance. Preservatives such as DMDM Hydantoin (dimethylol dimethyl hydantoin) and Kathon CG (mixture of methylchloro-isothiazolinone and methyl isothiazolinone) are known as effective preservatives at low levels, however, are not approved for use in leave-on cosmetic products in a number of countries. Phenoxyethanol and EDTA are widely accepted for use, however, are not satisfactorily effective at low levels. Parabens such as methyl paraben, propyl paraben, butyl paraben, and LiquaPar oil (mixture of isobutyl paraben, isopropyl paraben, and butyl paraben) are also widely accepted for use. However, because parabens are lipophilic, they cannot dissolve in water, and thus have some formulation constraints. Methyl paraben and propyl paraben are difficult to formulate at high levels, for they are solid at room temperature. Thus, there is also a desire to provide a foaming agent which can be used in hair mousse compositions in combination with a wide range of preservatives.
The type of propellants are also known to affect product performance. It is known that fluorohydrocarbons such as difluoroethane 152a (supplied by DuPont) can be used for a wide range of formulations. Propane and dimethyl ether can also be used for a wide range of formulations. However, propane is relatively combustible. Dimethyl ether when used at high levels can be corrosive. LPG (liquefied petroleum gas) is a mixture of mainly iso-butane, n-butane, and propane, and is available in different pressure grades. LPG is a relatively safe propellant, however, have some formulation constraints. Thus, there is also a desire to provide a foaming agent which can be used in hair mousse compositions in combination with a wide range of propellants.
Evaluation of product performance for hair mousse compositions vary depending on the purpose and concept of the product. In evaluating the performance of a hair mousse, one generally considers properties seen in three major stages; the properties of the foam upon dispensing from the package, the properties of the foam upon applying to the hair, and properties of the end results to the hair. Properties considered upon dispensing include volume of foam and foam expansion speed. It is known that when foam expansion is slow or delayed, "pooling" of the product occurs. Properties considered upon applying to the hair include stability and breakability of the foam, non-soapiness, smoothness, softness, creaminess, and stickiness. Properties considered on the end results to the hair include style control, dry or wet feel of hair, washability, shine, moisturizing, conditioning, anti-static, and brushing.
An attempt to achieve the above requirement, co-pending, commonly-assigned U.S. application Ser. No. 08/154,231(Y. Chen and T. Nambu) filed Nov. 18, 1993 discloses a foaming agent for leave-on foaming cosmetic composition comprising an amphoteric surfactant and an amine oxide.
However there remains a need for foaming cosmetic compositions contain no amine oxide. In Europe, there is an interest in a formula that does not use amine oxide for safety reasons.
Further there remains a need for foaming cosmetic compositions having improved clear and stable concentrations, especially, in the presence of a polymer, such as cationic type of water soluble polymer in the compositions.